<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    *{
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }
    body{
        display: flex;
        justify-content: center;
        align-items: center;
        min-height: 100vh;
        background: #000;
    }

    .loader{
        position: relative;
        width: 200px;
        height: 200px;
        overflow: hidden;
        -webkit-box-reflect: below 1px linear-gradient(transparent,#0005);
    }
    .loader:hover{
        background: #03e9f4;
        box-shadow: 0 0 5x #03e9f4,
         0 0 25px #03e9f4,
         0 0 50px #03e9f4,
         0 0 200px #03e9f4,
    }
    .loader span{
        position: absolute;
        display: block;
    }
    .loader span:nth-child(1){
        top: 0;
        left: -100%;
        width: 100%;
        height: 40px;
        background: linear-gradient(90deg, transparent, #03e9f4);
        animation: animate1 1s linear infinite;
        animation-delay: 0s;
    }
    @keyframes animate1 {
        0%{
            left: -100%;
        }
        100%{
            left: 100%;
        }
    }
    .loader span:nth-child(3){
        bottom: 0;
        left: -100%;
        width: 100%;
        height: 40px;
        background: linear-gradient(270deg, transparent, #03e9f4);
        animation: animate3 1s linear infinite;
        animation-delay: 0s;
    }
    @keyframes animate3 {
        0%{
            left: 100%;
        }
        100%{
            left: -100%;
        }
    }

    .loader span:nth-child(2){
        right: 0;
        top: -100%;
        width: 40px;
        height: 100%;
        background: linear-gradient(180deg, transparent, #03e9f4);
        animation: animate2 1s linear infinite;
        animation-delay: 0.5s;
    }
    @keyframes animate2 {
        0%{
            top: -100%;
        }
        100%{
            top: 100%;
        }
    }
    .loader span:nth-child(4){
        left: 0;
        top: 100%;
        width: 40px;
        height: 100%;
        background: linear-gradient(0deg, transparent, #03e9f4);
        animation: animate4 1s linear infinite;
        animation-delay: 0.5s;
    }
    @keyframes animate4 {
        0%{
            top: 100%;
        }
        100%{
            top: -100%;
        }
    }
</style>
<body>
    <div class="loader">
        <span></span>
        <span></span>
        <span></span>
        <span></span>
    </div>
</body>
</html>